HELIX-LYSINOE. 225 



is sometimes colored brown. This species differs from H. formosen- 

 sis in being more solid, more globose, much more narrowly umbili- 

 cated, the spire higher and more conic, etc. 



Var. trifasciata Schmacker & Boettger. Shell smaller, more^ 

 depressed, thinner ; color frequently darker, yellowish-tawny, always 

 trifasciate ; the aperture less distinctly lipped. 



Alt. 15, greater diam. 22, lesser 19 mill. (S. & .) 



Plain, at the foot of the Mts. 



This species belongs to a group of Helices containing H. bacca, 

 batanica and formosensis. They seem more closely allied to the 

 group of H. succincta than to any other. 



Section LYSINOE Ads. (Vol. IV, p. 69.) 



H. COLORADOENSIS Stearns. PI. 56, figs. 1, 2, 3. 



Shell orbicular, moderately depressed, spire slightly elevated, 

 apex obtuse, number of whorls four to four-and-a-half, rounded. 

 Umbilicus narrow, showing the penultimate whorl, though partially 

 covered by the reflection of the lip at the point of junction with 

 the base of the shell. Aperture obliquely ovate, nearly circular,, 

 and almost as broad as high.. Lip slightly thickened and reflected, 

 or simple, varying in this respect ; more reflected and aperture more 

 effuse at the columella. Parietal wall in the heavier examples cal- 

 loused, the callus connecting with the inner edges of the outer lip 

 above and below. Shell rather fragile, thin, translucent ; surface 

 smooth and shiny, and sculptured with fine incremental lines. Color 

 pale horn to white, and otherwise marked by a single narrow 

 revolving reddish-brown band just above the periphery, which in 

 some specimens is obscure or absent. In some individuals certain 

 faint scars upon the upper whorls imply an occasionally hirsute 

 character. (Stearns.*) 



Alt. 10}, greatest diam. 15}, least 13} mill, (largest spec.) 

 Alt. 8f, greatest diam. 13f, least 12 mill, (smallest adult.) 

 Grand Canon of the Colorado, opposite the Kaibab plateau, at an 

 elevation of 3,500 feet. 



Helix (Arionta) coloradoensis STEARNS, Proc. U. S. Nat. Mus. 

 1890, p. 206, t. 15, f. 6, 8, 12. 



The above, while exhibiting a facies or aspect of its own, is never- 

 theless suggestive of H. remondi Gabb, Mazatlan, in the Mexican 

 State of Sinaloa, and also from the high mesas or table-lands in the 

 15 



